.heart {
    margin: 0 auto;
}

.nav {
    position: relative;
    z-index: 1;
}

input,
button {
    width: 80%;
    height: 30px;
    border: none;
    margin-top: 10px;
}

.back-picture {
    position: fixed;
    width: 100%;
    max-width: 1260px;
    height: 100%;
    background-image: url(https://tse2-mm.cn.bing.net/th/id/OIP-C.TPRNmt-B4jm6WDrWzcrkcwHaEL?w=322&h=181&c=7&o=5&dpr=1.35&pid=1.7);
    background-size: 100% 100%;
    background-repeat: no-repeat;
}

.content h1 {
    padding-top: 22px;
    text-align: center;
    color: rgb(255, 255, 255);
}

.form-area {
    position: relative;
    top: 40%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 400px;
    height: 300px;
    border-radius: 10%;
    background-color: rgba(255, 255, 255, 0.5);
}

@media screen and (max-width:500px) {
    .nav {
        position: fixed;
        height: 100%;
    }
    .form-area {
        width: 80%;
        height: 280px;
    }
    .content h1 {
        padding-top: 12px;
    }
}

form {
    width: 100%;
    position: absolute;
    top: 50%;
    left: 60%;
    transform: translate(-50%, -50%);
}

.foot {
    max-width: 1260px;
    position: fixed;
    bottom: 0;
    z-index: 1;
}